Electric switch



April 14, 1931. c. F. SCHWENNKER 1,301,114

ELECTRIC SWITCH Filed May 11, 1929 I I .lil

I MM 1.

Invenl'or' Charles F. Schwennker',

HiSATTQr'ne Patented Apr. 14, 1931 UNITED STATES PATENT OFFICE CHARLES F. SCHWENNKER, F SCHENECTADY, YORK, A SS IGNOIR/ TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK ELECTRIC SW-ITCH' Application filed May 11,

My invention relates to electric switches and particularly to the construction of the cooperating contacts thereof. The object of my invention is the provision of an improved electric switch having contacts which are flexible and self adjusting in operation and inexpensive to manufacture.

Referring to the drawing, Fig. 1 is a side view of a portion of an oil switch having contacts constructed in accordance with my invention; Fig. 2 is a cross section on line 2-2 of Fig. 1 drawn to a larger scale; and Fig. 3

is a side view of Fig. 2.

In the drawing I have shown at 1 a portion of the tank of an oil switch in the top of which, not shown, are secured the insulator bushing 2 having studs 3 to which connect the fixed contacts now to be described. The switch which I have illustrated is adapted for the control of a heavy current circuit and accordingly has a double set of similar contacts as shown by Fig. 2 supported by the bifurcated contact block 4. Each arm of the contact block terminates in a flat end face 5 and extending upwardly from said face are several slots 6. WVithin each slot is a link 7 pivotally mounted on pin 8 having the head 9. Through the opposite end of each link 7 passes the rod 10 shown having a head at one end and a cutter pin at the other. The contacts 12 are arranged in pairs placed opposite each other. Each contact comprises a backing member 14'having wing portions 15 engaging pivot pin 10 and an intermediate portion 16 to which is securedas by rivets the contact finger 17 and the flexible connector 18. These flexible connectors 18 have their upper ends clamped to the contact block by the screws 19. They are of such a width that they nearly touch each other and serve to cover the slots 6. The single spring 20 having the form of a hair pin has its two end portions engaging the raised portions 22 on the backing members 14 and having its intermediate portion looped around and supported by the curved end of the link 7. This spring serves to yieldingly hold the contacts in a predetermined outward position in which position the ends of the contacts engage as.

stops the end face 5 of the contact block.

1929. Serial No. 362 381.

Each pair of opposed contacts may, however. move bodily a limited amount while the link 7 swings on its pivot to automatically aline with the movable contact now to be described. To the lower end of the operating rod 24 is secured the cooperating movable contact 25. This is shown as a rectangular frame 26 to the inner faces of opposite sides of which are attached as by rivets the main contact plates 27. To the ends-faces of the frame 26 are attached the arcing contact plates 28 which are shown somewhat longer than the main contact plates and which are adapted to contact with the fixed arcing contacts 30. The latter are pivotally supported on the contact block 4 and by springs 31 attached for convenience to the heads 9 ofjpins 8 are yieldingly held in the position illustrated. WVhen the switch is opened any arcing that may occur between the main contacts is at the outer face of the contact fingers I 17 and thus to a certain extent the spring 20 is shielded from the heat thereof. Further protection of the spring from the heat of the arc is afforded by reason of the fact that the intermediate portion of the spring is carried back and looped over the rear of the link 7. This portion of the spring is also protected from hot. gases arising from the outer faces of the contacts by the flexible connections 18 which. as has already been pointed out above cover the slots.

I have chosen the particular embodiment described above 'as illustrative of my invention and it will be apparent that various modifications may be made without departing from the spirit and scope of my invention which modifications I aim to cover by the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An electric switch having a contact supporting block, opposed contacts having flexible connections therewith, a contact supporting link pivoted at opposite ends to said block and to said contacts, and a spring having its opposite ends engaging the contacts and arranged to hold the contacts in a, predetermined position, said spring having a portion remotely positioned with respectto said ends and thetips of said contacts. 7

V 2. An electric switch having a contact supporting block, a pair of opposed contacts each having a flexible connection with said block,

a contact supporting link pivoted at opposite ends to said block and to said contacts,

and a spring having its opposite ends engagmg the contacts and extending over said link at a' point adjacent said block and remote.

from the tips of said'contacts for holding the contacts in a predetermined position.

3. An electric switch having a fixed contact supporting block, a pair of opposed contacts each having a flexible connection with said block, a link pivoted at one end to said block and pivoted at theotherend to said contacts, and a spring comprising a loop having its ends arranged to engage the respective contacts and having'its intermediate loop portion supportedby and extending frearwardly oversaid' link. I I

4:. An electric switch having a fixed contact supporting block, a pair of opposed contacts, said contacts being adapted to engage a stop surface on said block for limiting movement thereof, flexible conductor strips between the block and the contacts, a link pivoted at opposite ends to the block and the contacts, a spring adapted to separatethe contactsand arranged'to extend rearwardly I over said link and between said strips, and movable contacts arranged to engage the outer faces of said opposed contacts.

5. An electric switch having a fixedcon- V tact supporting block, a plurality of pairs of opposed contacts arranged in alinement and each having a flexible connection with 7 said block, a supporting link for each of said pairs of contacts, a pivot rod for said links supported by the block, a. pivot rod for said pairs ofcontacts supported by said links, a sprmg for each pair ofcontacts having its ends engaging the respective contacts of a pair and having itsintermediate portion extending rearwardly in a loop around thecorresponding link and arranged'between the flexible connections, and a movable contact member comprising a pair of opp'osedplates arranged when the switch is closedto engage the outer faces of said contacts' In witness whereof, I have hereunto set 7 my hand this 10th day of May, 1929.

CHARLES 1 SCHWENNKER. 

